No. You have a fundamental misunderstanding of PHP. PHP runs on the server. It creates HTML and/or JavaScript and sends it to the requesting client. It cannot access anything on the client, unless the client sends it information.

I ♥ ManiacDan & requinix

This is a sig, and not necessarily a comment on the OP:Please don't be a help vampire!

No. You have a fundamental misunderstanding of PHP. PHP runs on the server. It creates HTML and/or JavaScript and sends it to the requesting client. It cannot access anything on the client, unless the client sends it information.

So you can only detect which mobile device a user is using but you cannot check if a certain app is installed on the mobile device?

Correct, because the browser is sending a User-Agent string that allows you to identify the browser being used, from which you can deduce (if the browser's not lying) what the device is. I don't think a mobile browser will send you its list of installed apps willingly; seems a security breach to me, but I don't do mobile development.

I ♥ ManiacDan & requinix

This is a sig, and not necessarily a comment on the OP:Please don't be a help vampire!

You can't get a list of apps because the browser would need special filesystem permissions which would throw a bunch of red flags while actually installing the thing.

When I install a browser on my phone, the phone alerts me that the browser is requesting permission to access certain things on the phone (internet connection, control of screen brightness, key overloading, etc). It would need further permissions to see open/installed apps, that's a whole other set of permissions.

Correct, because the browser is sending a User-Agent string that allows you to identify the browser being used, from which you can deduce (if the browser's not lying) what the device is. I don't think a mobile browser will send you its list of installed apps willingly; seems a security breach to me, but I don't do mobile development.

Thank you for the explanation. I assumed that if I could detect devices I could also detect if a certain app is installed on said device with PHP. I'll have to look into the Javascript solution.